Who's at risk for iron deficiency?
Iron deficiency is the most common nutrient deficiency across the globe. It most commonly affects young children (ages 6 to 24 months), those who are menstruating, pregnant women, athletes, older adults (over 60), or those with certain medical conditions (celiac disease, parasitic infection, chronic kidney disease). In the US, about 1 in 3 adults may have iron deficiency.
Iron deficiency progresses in three consecutive stages
Stage 1: iron stores become depleted; lab test will show low serum ferritin
Stage 2: decreased transport iron (transferrin) and reduced iron supply to the cells.
In these first two stages, iron deficiency is present without anemia.
Stage 3: low hemoglobin from insufficient iron supply, which results in anemia.
Iron deficiency often occurs because of either inadequate intake (such as, veganism without supplementation), chronic blood loss (such as from menstruation or a GI bleed) or poor absorption (celiac), or increased demands (pregnancy, sports).
Athletes often have higher iron needs and higher iron losses for a variety of reasons. Iron is an essential mineral that’s an important component of oxygen transport and energy production. Iron deficiency anemia is strongly related to reduced athletic performance.
Signs & Symptoms of Iron Deficiency
Fatigue
Weakness
Shortness of breath
Impaired Cognition
Difficulty Concentrating
Decreased immune function
Reduced exercise performance
Poor body temperature regulation
GI disturbances
Assessing Iron Status
The following blood tests can help reveal one’s iron status:
Complete Blood Count (CBC) - this will give an overview of the red blood cells, white blood cells, platelets, hemoglobin, hematocrit, and cell volume and size (MCV, RDW, MCH, MCHC)
Iron Panel: serum iron, ferritin, total iron binding capacity (TIBC), and transferrin
Typically, iron status will progress in the following way:
First the ferritin drops (storage, like your iron savings account)
Next, the transferrin will drop
Lastly, your hemoglobin will drop
Why is Iron Important?
It’s a crucial part of hemoglobin, which carries oxygen to muscles (via the red blood cells) during exercise. Without adequate iron, the body can’t produce enough hemoglobin and thus, the muscles receive less oxygen.
It is essential for cellular processes that produce energy (ATP)
Iron aids in repair and regeneration of muscle tissue
It keeps the immune system strong by producing antibodies and aiding in other cellular activity.
Optimizes performance by increasing exercise tolerance, stamina and cognitive function.
How much iron is needed?
Iron needs vary by age group and life stage.
Male
7 to 12 months: 11 mg
1 to 3 years old: 7 mg
4 to 8 years old: 10 mg
9 to 13 years old: 18 mg
14 to 18 years old: 11 mg
19 to 50 years old: 8 mg
51+ years old: 8 mg
Female
7 to 12 months: 11 mg
1 to 3 years old: 7 mg
4 to 8 years old: 10 mg
9 to 13 years old: 18 mg
14 to 18 years old: 15 mg
19 to 50 years old: 18 mg
51+ years old: 8 mg
Pregnancy: 27mg
Lactation: 9 to 10 mg
Iron in Food
There are two types of iron in food: heme and non-heme. Much of the iron in meat is heme iron, which is more easily absorbed from food and used by your body. Plant foods contain only non-heme iron. Although plant foods are high in iron, it is often attached to compounds that reduce its absorption. These compounds are called phytates and are found in whole grains and dried beans.
Compounds in coffee and tea also reduce iron absorption, as do calcium supplements. Vitamin C can counter the effects of some of these compounds. Eating vitamin C-rich foods and iron-rich foods at the same time can increase iron absorption. Good sources of vitamin C include oranges, grapefruits, strawberries, green leafy vegetables (kale, collards, Swiss chard), broccoli, Brussel sprouts, bell peppers (yellow, red, and green), and cauliflower.
The following ideas may help to increase iron absorption and/or add more iron to your meals:
-Include vitamin C-rich foods in meals
-Drink coffee and tea between meals rather than with them
-Separate calcium and zinc sources (esp. supplements) from your iron-rich meals, if possible
-Cook using cast-iron cookware or consider purchasing a “Lucky Iron Fish” which can be used when cooking on the stovetop.
Heme Iron Sources:
Beef
Poultry
Oysters, mussels and clams
Tuna
Sardines
Chicken and beef liver
Organ meats
Non-Heme Iron Sources:
Beans
Lentils
Spinach and most dark leafy greens
Dark chocolate (greater than 45%)
Nuts and seeds, especially pumpkin seeds, sesame, hemp and flax
Fortified breakfast cereals
Fortified bread and rice
Vitamin C-RicH Foods to Increase Iron Absorption:
Pair these with non-heme iron foods to increase the absorption of iron.
Citrus fruits (oranges, lemons and grapefruit)
Broccoli
Cauliflower
Brussels sprouts
Bell peppers
Watermelon
Cantaloupe
Strawberries, raspberries and blueberries
Pineapple
Tomatoes
Winter squash
Potatoes (sweet and white)
The best way to know that you're getting the nutrition your body needs is to meet with a registered dietitian for an assessment. Schedule a Q&A call to discuss working with a dietitian.
References:
Smith JW, Holmes ME, McAllister MJ. Nutritional Considerations for Performance in Young Athletes. J Sports Med (Hindawi Publ Corp). 2015;2015:734649. doi: 10.1155/2015/734649. Epub 2015 Aug 19. Erratum in: J Sports Med (Hindawi Publ Corp).
World Health Organization. Nutrition in Adolescence—Issues and Challenges for the Health Sector. Geneva, Switzerland: WHO; 2005.
Hinton P. S. Iron and the endurance athlete. Applied Physiology, Nutrition, and Metabolism. 2014;39(9):1012–1018. doi: 10.1139/apnm-2014-0147
Institute of Medicine (U.S.) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC, USA: National Academy Press; 2001